Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Caribou ME
908 am EST Monday Mar 2 2015
low pressure south of Nova Scotia will rapidly move off to the
northeast today. An Arctic cold front will cross the area this
evening. High pressure will build toward the area tonight and
Tuesday from the west. Another low will cross the region Tuesday
night into Wednesday.
Near term /through tonight/...
900 am update...adjusted the probability of precipitation upward to account for the steady
snow ongoing at this time per the radar and observation. The rest of the forecast
looks to be in order at this time west/the expected snow squalls this
afternoon. Will enhance the wording in our hazardous weather
outlook to account for the snow squall potential and strong wind
some sunny breaks may occur by early afternoon and allow
temperatures to reach the upper 20s to lower 30s. This will
destabilize the atmosphere ahead of an Arctic front that will
enter northern zones late this afternoon and sweep across the
forecast area this evening. The instability and steepening low-
level lapse rates are expected to cause some locally heavy snow
squalls this afternoon...most likely in northern Aroostook where
snow squall parameters are giving very strong signals. Tops on
these squalls will likely exceed h700. The squalls may drop a
quick inch or two of snow with quarter mile visibilities and winds
gusting over 40 miles per hour. This will make for very hazardous driving
conditions towards Presque Isle and Caribou late this afternoon
into early evening. The squalls are projected to dissipate south
of Houlton. The Arctic front will bring sharply colder
temperatures and very strong winds through the evening with
northwest winds gusting to 35 miles per hour well into the night. The strong
cold air advection and these winds have prompted a Wind Chill
Advisory in The Crown of Maine later tonight with wind chills
dipping to 25 below. The subzero wind chills will spread all the
way to the coast later in the night.
Short term /Tuesday through Wednesday/...
strong high pressure will build in from the west Tuesday morning
then crest over the region in the afternoon. Low pressure will
approach from the west Tuesday night then pass to the northwest
Wednesday. Expect over-running precipitation ahead of this system.
Also expect most precipitation to be in form of snow... although
there may be a brief change to rain along the coast. Will use
model consensus and blend the NAM... GFS and European model (ecmwf) for quantitative precipitation forecast.. sky
and probability of precipitation. Have used office snow from thickness tool for snowfall
amounts. Will use the super blend for temperature and dew point.
Mosg25 was used for winds.
Long term /Wednesday night through Sunday/...
strong cold advection will take place again Wednesday night
behind departing low pressure to the north. Strong high pressure
is expected to build in from the west Thursday and crest over New
England Friday. Low pressure will approach from the northwest
Friday night and Saturday bringing light snow to the region. High
pressure will then build in from the northwest Sunday. Have used
the mosg25 to initialize grids.
Aviation /14z Monday through Friday/...
near term: IFR north of hul early this morning in snow...then
predominately MVFR due to snow and ceilings through midday for all
sites. This afternoon and evening will be VFR with the exception
of snow squalls late this afternoon and early evening for
pqi...car and fve. These squalls could be heavy with 1/4 Michigan visible
and 35 miles per hour gusts.
Short term: expect VFR conditions Tuesday. IFR conditions are
expected Tuesday night into Wednesday morning. VFR conditions
expected Wednesday afternoon into Friday.
near term: have extended the gale two extra hours late tonight and
added an freezing spray advisory late tonight into early Tuesday
morning. Increased gusts with the gale to 45 knots this evening.
Short term: for sustained winds have used the nam12 into
Wednesday then transition to the super blend winds. For waves:
expect increasing southerly wind wave Tuesday night as low
pressure approaches from the west with a significant southerly
fetch developing across the Gulf of Maine. Will use the near shore
wave model for waves.
ME...Wind Chill Advisory from 2 am to 7 am EST Tuesday for
Marine...freezing spray advisory from 1 am to 10 am EST Tuesday for
Gale Warning from 3 PM this afternoon to 6 am EST Tuesday for